Atmospheric Residual Layers: WRF/HYSPLIT Modeling for Better Understanding in Complex Terrain

Friday, 19 December 2014
Frank Freedman and Sen Chiao, San Jose State University, San Jose, CA, United States
We will present numerical modeling results of the atmospheric residual layer in a complex terrain environment. The focus of this study is to test the validity in field situations of the classical explanation that the residual layer is remnant air from the previous day's upwind convective boundary layer. The Advanced Research Weather Research and Forecasting (WRF-ARW) model will be employed to simulate selected cases of the MATERHORN field experiment in Dugway Proving Grounds (Northern Utah). The simulation results will be evaluated using observed soundings and lidar measurements taken during this field study. The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) will then be used to generate back-trajectories of residual layer air to test the hypothesis that residual layer scalar profiles are as classically explained, a result of advection of upwind convective boundary layer air from the end of the previous day. The research fits into a broad stable boundary layer context since it investigates an aspect of the stable boundary layer - the residual layer - that could potentially be underappreciated in explaining stable boundary layer variability.